The invention relates to a method for manufacturing a flat textile structure, in which at least two melts of at least two polymers are changed to the form of fibers with the aid of a spinning device, and in which the fibers are then combined and then solidified.
The general type of this method is known from DE-OS 15 60 800 (the contents of which are incorporated herein by reference). This method is suitable for manufacturing mixed-fiber fleece, with different polymers being spun alternately in the melt spinning method. Unfortunately, the filtration properties of the fleece produced by this method are not very satisfactory.
There remains a need for improvements to the known type of a method of manufacturing a spun fleece in such a way that filtration elements made of fiber fleece materials produced thereby exhibit good filtering properties across a long service life.
Devices configured for practicing this method generally comprise a spinning rotor, capable of being given a rotary motion around its axis, that has outlet openings in the vicinity of its circumferential surface. The rotor has first auxiliary means movable transversely with respect to the axis for continuously capturing the fibers emerging from the outlet openings.
Such a device is set forth in DE-OS 38 01 080, in which only one polymer is melted and fed under pressure into the spinning rotor. The molten streams emerging from the outlet openings are deflected by a blower, stretched, and laid down on a first auxiliary means, a backing fleece. Besides the disadvantage that the fleece formed by this device is not suitable as filter fleece, since it does not guarantee a sufficiently high filter effect over a long service life, the reliability of the device is less satisfactory when used for the intended purpose. With increasing usage, the known device with pressurized feed of the melt into the spinning rotor has a tendency to develop leaks.
There remains a need for an improved rotor device that provides better operational characteristics across a long service life in the manufacture of filter fleeces that provides a high filter effect over a long service life.